The invention relates to the continuous production of para-cumylphenol and, in particular, to the stabilization of color using hypophosphorous acid.
Para-cumylphenol is prepared by the reaction of purified phenol and alpha-methylstyrene in the presence of an acidic catalyst. During the process, the reaction effluent stream is stripped of the phenol solvent carrier in a stripper column and later subjected to nitrogen desorbing to remove residual phenol and other volatile impurities. Long residence times in the phenol stripping column and the nitrogen desorber have resulted in thermal/oxidative degradation of the para-cumylphenol product, leading to significant color formation which is undesirable.